Mechanical stoker structure



lR. A. FORESMAN MECHANICAL STOKER STRUCTURE July 6 1926.

Filed `July 15l 1920 2 sheets-shed 1 v C NNTOR f July 6 1926.

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R. A. FORESMAN MCHNICAL STOKER STRUCTURE I Filed YJuly 15. 1920 2 SheeJts-Sheet 2 Patented July 6 1926.

UNITED STATES PATENT OFFICE.

ROEERT A. FORESMAN, OF ESSINGTON, PENNSYLVANIA, ASSIGNOR-TON WESTING- HOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION F PENN- SYLVANIA.

MECHANICAL STOKER STRUCTURE.

Application led July 15, 1920. Serial No. 396,378.

This invention relates to stoker structures, and particularly to stokers of the underfeed type wherein rows of-'tuyres and fuel-feedingretorts are alternately arranged in parallel relation and inclined from the front wall of the furnace to the dump lgrate. The invention has for an object the provision of a.

grate surface composed of parts of simple and durable construction which may be -0 readily assembled or replaced without mauniformly distributed over the entire width of the furnace in the vicinity of the dump grate or the area where final combustion 'of the fuel takes place.

These and other objects are attained by means of a stoker construction embodying the features herein described and illustrated in the drawings accompanyigand forming a part hereof, wherein:

c Fig. 1 is a longitudinal' through a Stoker structure embodyingmy invention.

.,Fig. 2 is a plan view of a fragment of the grate of the Stoker illustrated in Fig. 1, parts being shown in section taken on line II-'II of F10. 1.

Referring to the drawings, the stoker includes fuel feeding hoppers 5 which may be of any preferred construction. The discharge channels 6 of the hoppers extend beneath the front wall 7 of the furnace and l fuel is forced through the channels by means of reciprocating plungers 8 which mayI be operated in any desired manner. A casting 9 which extends entirely across the widt of the furnace serves to support and to aline i the discharge channels 6 of the fuel hoppers A5 which are arranged in spaced parallel relation2 as indicated in Fig. 2. The hopper castings 5 are bolted or otherwise secured to the front casting 9, as by bolts 9', and the hoppers and the front casting are supported upon an I-beam 11 which is mounted uponv any Suitable foundation such as that indcated at 12. y

Spaced from the front support and cxvertical section tending across the furnace is a rear gratesupport casting 13 mounted upon structural` frameslt which may be mounted directly upon the foundations beneath the casting or supported by the side walls ofthe furnace.. The rear casting 13` andthe front casting 9 are connected at spaced intervals by means of frames fabricated from commercial shapes. j

In the construction illustrated, each frame includes an upper strut 15 and a lower strut 16 formed of angle iron.y The ends of thc struts are bolted securely to the casting 13 and upper side wall plates 17v and form a connection therefor, which may expand and contract with variationsin temperature without danger of damage. Side plates 17 which are formed in sections and which may be made either of cast or plate iron, are bolted to the upper and lower struts and form the side walls of the retorts. Sectional bottom' plates 18 are placed across the space between the two adjacent framesand rest upon the struts 16 to which they are bolted. The side and bottom plates form a retort which extends from the discharge channel Aof the hopper to a point above the casting 13. The casting 13 1s so formed that a continuation of the retort bottom extends to the lower end of the grate to be hereinafter described.

Rows of tuyres 19 are mounted upon the Sides of adjacent retorts and extendfrom a pointl adjacent the front wall of the furnace to the lower end of the grate and overlap a dump ate 21 which extends entirely across the wi th of the grate and is pivoted to the casting 13 at 22.

Tuyres 23, Similar in construction to the tuyres 19, are placed in the lower end of the retort and form, together with the .tuyres' 19,` a continuous grate surface ex'nding across the width of the furnace, through which air from the air box 24 and beneath the grate may pass to the fuel. The casting 13 is provided with an air box 25 which receives air from the box 24 and delivers air to the tuyres resting thereon and through the hollow dump grate. This construction provides' a continuous active grate surface over an extensive area adjacent the ash pit and facilitates the combustion of fuel to completion.

Each retort maybe provided with a secondary or auxiliary ram 26 which recipro# connected to a driving means, not shown, by

means of a connecting rod 27 which extends forwardly and projects through an upper casting. i i

While I have described and illustrated but one embodiment of lmy invention', it will be apparent to those skilled in the art that various changes, modifications, additions and omissions may be made 'in the apparatus dcscribed and illustrated without departing 5 from the spirit and scope of my invention as set forth by the appended claims;

What I claim is:

1. In an underfeed stoker, an inclined grate comprising a retort having la bottom the lower portion ofsaid retort bottom being formed of a pluralityof tuyre blocks su erimposed one on the other in stepped re ation and having tuyre openings for discharging air rearwardly` into the retort.

2. In an -ilnderfeed Stoker, an inclinedgrate comprising a plurality of inclined anks of tuyres and retorts between adn" jacent tuyre banks, each retort beine` of progressively decreasing depth from front to rear, the bottom of each retort being formed at its lower shallow end of a pluy grate structure comprisin downwardly inclined from front to rear,

nating fuel retorts and'downwardlyqnclined f banks of tuyres, the bottom of each retort being provided adjacent its lower end with a plurality of tuyre blocks superimposed one onthe other in stepped relation, the refuse discharging mechanism including a transverse member for supporting the lower end of 'the grate and supplying air to the tuyre openings.

4. In an underfeed stoker, an inclined a plurality of tuyre banks alternatingwlth a plurality of retorts vhaving bottoms inclined from front to rear, the lower portion of each of said retort bottoms being formed of a plurality of tuyre blocks superimposed one on the other in stepped relation and having tuyrc openings for discharging air 'rearwardly into the retort.

In testimony whereof, I have hereunto subscribed my name this 18th day of July, 1920.

R. A. FRESMAN. 

